Ink jet recording method and recording apparatus

ABSTRACT

An ink jet recording method includes using at least a first ink composition containing a color material and a second ink composition containing a resin as well as substantially not containing a color material, including: a first recording step recording the first ink composition onto a medium to be recorded; a second recording step recording the second ink composition onto the image; a second drying step of drying the image at a first temperature, which is performed during execution of the second recording step or thereafter; and a third drying step of drying the image at a second temperature which exceeds the first temperature after the second drying step; in which, the second ink composition does not substantially contain an aprotic polar solvent, and the heat deformation temperature of the resin exceeds the first temperature and is lower than the second temperature.

Priority is claimed under 35 U.S.C. §119 to Japanese Application No.2012-005375 filed on Jan. 13, 2012 and Japanese Application No.2012-085202 filed on Apr. 4, 2012, both of which are hereby incorporatedby reference in their entirety.

BACKGROUND

1. Technical Field

The present invention relates to an ink jet recording method and arecording apparatus.

2. Related Art

In the related art, various systems have been used as recording methodsfor forming an image on a medium to be recorded based on an image datasignal. Among these, the ink jet method performs image formationdirectly on the medium to be recorded by ejecting ink to only necessaryimage portions using a low cost apparatus, and therefore can use inkefficiently and has low running costs. Furthermore, since the ink jetsystem makes little noise, it is an excellent recording method.

In recent years, a method is being focused on in which a colorlesstransparent clear ink is printed as a finishing coat after printing animage of colored ink, in order to increase the quality of the image.

For example, in JP-A-2010-221634, a method is disclosed in which an inkset provided with color inks and a clear ink containing a resin isprepared, and printing is performed on normal paper or high qualitypaper using the ink jet method. In addition, in the printing, first, apatch or image of color ink is printed onto the medium to be recorded,then subsequently, the clear ink is solid printed onto the printingregion of the color ink, and finally, the medium to be recorded is driedby heating using a heater (see paragraph [0067] of the specification ofJP-A-2010-221634).

However, in a case in which the finishing coat of the clear ink isapplied at (approximately) the same time as the coating of the color ink(colored ink), as in the printing method disclosed in JP-A-2010-221634,an issue occurs in that the glossiness is poor. In addition, there arecases in which the ink disclosed in JP-A-2010-221634 adheres to thevicinity of the ink jet head, and a problem occurs in that the ink jethead clogging stability is poor.

SUMMARY

An advantage of some aspects of the invention is that it provides an inkjet recording method with excellent glossiness and ink jet head cloggingstability.

The invention can be realized in the following forms or applicationexamples.

Application Example 1

According to an application example, there is provided an ink jetrecording method using at least a first ink composition containing acolor material and a second ink composition containing a resin as wellas substantially not containing a color material, the method including:a first recording step of forming an image by recording the first inkcomposition onto a medium to be recorded which is non-absorbent orpoorly absorbent to ink using an ink jet head; a second recording stepof recording the second ink composition onto the image using the ink jethead; a second drying step of drying the image at a first temperature,which is performed during execution of the second recording step orafter the second recording step; and a third drying step of drying theimage at a second temperature which exceeds the first temperature, andis performed after the second drying step, in which, the second inkcomposition does not substantially contain an aprotic polar solvent, andthe heat deformation temperature of the resin exceeds the firsttemperature and is lower than the second temperature.

According to the ink jet recording method of the application example,even if recording using the second ink composition is performed on theimage of the first ink composition in the second recording step bydrying the image formed using the second ink composition at the firsttemperature, it is possible to obtain favorable ejection stability ofthe second ink composition, and a recorded object of a clear image. Inaddition, by performing a third drying step at a second temperature,which is higher than the first temperature, it is possible to fix animage formed using the second ink composition. Since the second inkcomposition does not substantially contain a color material and is aso-called clear ink composition, the rough surface appearance orirregular appearance of the image surface is almost entirely eliminatedby the drying at the second temperature, and it is possible to obtain ahighly glossy recorded object.

Application Example 2

In the ink jet recording method according to the above describedapplication example, the resin is one or more types selected from anacrylic resin, a urethane resin, a polyester resin, and astyrene-acrylic resin.

According to the application example described above, it is possible toform a recorded object with excellent glossiness, and to obtain arecorded object with excellent durability by giving it higher colorfastness to rubbing.

Application Example 3

In the ink jet recording method according to the above describedapplication examples, the first recording step is executed during theperformance of the transporting operation of the medium to be recordedin the forward direction, and the second recording step is executedduring the performance of the transporting operation in the forwarddirection, which is executed during the performance of the transportingoperation of the medium to be recorded in the reverse direction or afterthe transporting operation in the reverse direction has ended.

According to the application example described above, it is notnecessary to provide the ink jet head in the ink jet recording method,which is a recording unit used in the recording step, and the heatingapparatus such as the heater as a drying unit used in the drying step ineach recording step, and it is possible to configure the recordingapparatus using the minimum number of heads and heating apparatuses,therefore it is possible to obtain a miniature recording apparatus.

Application Example 4

In the ink jet recording method according to the above describedapplication examples, the dryness factor of the image formed by thefirst recording step before the second recording step is 60% or higher.

According to the application example described above, even if recordingusing the second ink composition is performed on the image of the firstink composition in the second recording step by drying the image formedusing the first ink composition at the first temperature to a drynessfactor of 60% or higher, it is possible to suppress the occurrence ofbleeding between an image derived from the first ink composition, andthe second ink composition, and it is possible to obtain a recordedobject with a clear image.

Application Example 5

In the ink jet recording method according to the above describedapplication examples, the method includes a first drying step of dryingthe image at a first temperature performed during execution of the firstrecording step or before the second recording step, and the secondrecording step includes a step in which the second ink composition isrecorded onto the image formed by the first recording step, and afterthe second ink composition on the medium to be recorded has dried, thesecond ink composition is re-recorded.

According to the application example described above, by forming twolayers or more of the second ink composition which does notsubstantially contain a color material, that is the so-called clear inkcomposition, it is possible to obtain a recorded object in which theglossiness and the color fastness to rubbing are yet further improved.

Application Example 6

In the ink jet recording method according to the above describedapplication examples, the ink jet head used in the first recording stepis provided with nozzle rows formed from a plurality of nozzle holes,and scans in a main scanning direction through a scanning mechanism; thenozzle rows include a first nozzle row in which a plurality of thenozzle holes for ejecting the first ink composition are arranged in asub-scanning direction intersecting the main scanning direction, and asecond nozzle row in which a plurality of the nozzle holes for ejectingan undercoat ink composition which records an undercoat layer of theimage are arranged in the sub-scanning direction; and the firstrecording step uses the first nozzle row and the second nozzle rowdivided in the sub-scanning direction into groups which respectivelyinclude a predetermined number of the nozzle holes, records theundercoat ink composition using a first group in an upstream side in thesub-scanning direction, and, records the first ink composition using asecond group further to a downstream side in the sub-scanning directionthan the first group.

According to the application example described above, it is possible toachieve high-speed recording by arranging the nozzle rows in a dividedmanner. In addition, by arranging the nozzle rows in a divided manner,it is possible to obtain a specific recorded object in which it is notnecessary to perform so-called back-feed recording, in which recordingis performed using a combination of the forward direction and reversedirection of the transport direction of the medium to be recorded, orthe number of back-feeds may be reduced.

Application Example 7

According to another application example, there is provided a recordingapparatus, in which an image is formed on the medium to be recordedusing the ink jet recording method described above.

According to the recording apparatus of the application example, it ispossible to easily obtain a recorded object with excellent glossinessand color fastness to rubbing while using a small recording apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a block diagram showing the configuration of a printeraccording to a first embodiment.

FIG. 2 is a schematic cross-sectional view of the vicinity of the headof the printer according to the first embodiment.

FIG. 3 is a schematic view illustrating the recording unit using dividednozzle rows of the printer according to the first embodiment.

FIG. 4 is a graph for calculating the dryness factor in the first dryingstep.

FIG. 5 is a table showing a list of ink compositions used in theexamples.

FIG. 6 is a table showing the results of a redispersibility evaluationof the resin emulsion contained in the second ink composition.

FIG. 7 is a table illustrating the recording method in the examples.

FIG. 8 is a table showing the examples.

FIG. 9 is a graph showing the glossiness in the examples.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Below, a detailed description will be given of aspects for embodying theinvention. Furthermore, the invention is not limited to the followingembodiments, and various modifications thereof may be made within thespirit of the invention. Furthermore, in the invention, in some cases,the first ink composition and the second ink composition are bothreferred to as the “ink composition”. In the invention, the “firsttemperature” and the “second temperature” refer to the temperature ofthe surface of the medium to be recorded which makes contact with theink composition. It is possible to measure these temperatures using acommercially available thermography apparatus. Specific examples of thethermography apparatus include the infrared thermography apparatusH2640/H2630 (trade names), (manufactured by NEC Avio InfraredTechnologies Co., Ltd.).

First Embodiment Ink Jet Recording Apparatus

The ink jet recording apparatus (hereinafter, also referred to as simplythe “recording apparatus”) according to the first embodiment of theinvention is not particularly limited, as long as the apparatus ejectsan ink composition from a head to perform recording while relativelymoving an ink jet head for ejecting the first ink composition and an inkjet head for ejecting the second ink composition (hereinafter, alsoreferred to as simply the “heads”) in relation to the medium to berecorded. Furthermore, the head for ejecting the first ink compositionand the head for ejecting the second ink composition may each bedifferent heads, and may also be the same head as one another.

An off-carriage type serial printer (hereinafter, also known as simplythe “printer”) will be exemplified as the recording apparatus accordingto the present embodiment and illustrated with reference to thepictures. Here, a serial printer performs recording while the headreciprocates in a direction that intersects the transport direction ofthe medium to be recorded. Among these, an off-carriage type serialprinter is a printer in which the ink cartridge in which the inkcomposition is stored and the head on the carriage are connected by atube. Furthermore, in the figures used in the following description, thescale of each member is appropriately changed to make each member avisually recognizable size.

FIG. 1 is a block diagram showing the configuration of a printer 1. FIG.2 is a schematic cross-sectional view of the vicinity of the head of theprinter 1. Here, the horizontal direction (Y) of the paper face shown inFIG. 2 corresponds to the direction (path) in which the medium to berecorded is transported.

The printer 1 according to the present embodiment is an apparatus whichforms an image on the medium to be recorded P by ejecting the first inkcomposition and the second ink composition in this order toward themedium to be recorded P which is non-absorbent or poorly absorbent toink (hereinafter, referred to as simply the “medium to be recorded”).Here, the printer 1 can form an image using ink compositions of variouscolors, and examples of printing that uses the first ink compositioninclude, for example, forming an image using ink compositions of thefour colors of CMYK, or forming an undercoat which gives excellentopacity to the medium to be recorded P using a white ink composition. Inaddition, examples of printing that uses the second ink compositioninclude, for example, applying a finishing coat of a clear inkcomposition on the first ink composition, thereby it is possible toincrease the appearance of glossiness.

The printer 1 includes a transport unit 10, a carriage unit 20, a headunit 30, a heater unit 40, a detector group 50, and a controller 60. Theprinter 1 that received the printing data from the computer 100 which isan external apparatus controls each unit (the transport unit 10, thecarriage unit 20, the head unit 30, and the heater unit 40) using thecontroller 60. The controller 60 forms an image on the medium to berecorded P by controlling each unit based on the printing data receivedfrom the computer 100. The situation within the printer 1 is monitoredby the detector group 50, and the detector group 50 outputs thedetection result to the controller 60. The controller 60 controls eachunit based on the detection results output from the detector group 50.

The transport unit 10 is for transporting the medium to be recorded P,such as paper, in a specific direction (hereinafter, referred to as the“transportation direction” or the “sub-scanning direction”). Thistransport unit 10 includes a paper feed roller 11, a transport motor(not shown), a transport roller 12, a platen 13, and a paper outputroller 14. The paper feed roller 11 is a roller for feeding the mediumto be recorded P, which is inserted into the paper insertion opening,into the printer 1. The transport roller 12 is a roller which transportsthe medium to be recorded P, which is fed by the paper feed roller 11,to a printable region, and is driven by the transport motor. The platen13 supports the medium to be recorded P during printing, and the mediumto be recorded P is fed over the platen 13 using the drive of the paperfeed motor (not shown). The paper output roller 14 is a roller whichdischarges the medium to be recorded P to an outer portion of theprinter, and is provided to the downstream side in the transportdirection in relation to the printable region.

The carriage unit 20 is a movement mechanism which moves, in otherwords, scans the head 31 in a direction (hereinafter, referred to as the“movement direction” or the “main scanning direction”) which intersectsthe transport direction (the sub-scanning direction) while ejecting theink composition in relation to the medium to be recorded P which isstopped on the printing region. The carriage unit 20 includes a carriage(not shown) and a carriage motor (not shown). The carriage is providedwith a head 31 on the inner portion thereof, and communicates with thecarriage motor (not shown) via a timing belt (not shown). The inkcartridge (not shown) is installed in a different location to thecarriage, and is stored in the cartridge storage portion (not shown)provided on the outside of the printer 1 main body (the outside of themovement range of the carriage). An ink supply tube (not shown) connectsbetween the ink cartridge and the carriage. In this case, the inkcartridge and the carriage do not move together. Furthermore, thecarriage reciprocates along a guide shaft of the carriage motor in astate of being supported by the guide shaft that intersects thetransport direction described below. The carriage is supported by theguide shaft to be reciprocally movable in the axial direction of theguide shaft.

The head unit 30 is for ejecting the first ink composition and thesecond ink composition in relation to the medium to be recorded P. Thehead unit 30 is provided with a head 31 which includes a plurality ofnozzle holes. Since the head 31 is provided on the inner portion of thecarriage, when the carriage moves in the movement direction, the head 31also moves in the movement direction. In addition, the head unit 30ejects the first ink composition and the second ink composition inrelation to the medium to be recorded P while the head 31 moves in themovement direction. Accordingly, a row of dots is formed on the mediumto be recorded P along the movement direction.

In this manner, the head 31 ejects the first ink composition and thesecond ink composition in relation to the medium to be recorded P, andthereby it is possible to simplify the printer 1 as a recordingapparatus.

The heater unit 40 is provided with a heating unit for drying and fixingan image formed by the ink composition ejected onto the medium to berecorded P. The heating unit is provided with a drying heater 41 whichheats to a first temperature at which the ink composition ejected andattached to (landed on) the medium to be recorded P is dried to aspecific dryness factor, and a curing heater 42 which further heats andcures the image, which was dried at the first temperature, at atemperature higher than the first temperature and fixes the image to themedium to be recorded P. In addition, an air blower 43 may also beprovided in the heater unit 40 in order to promote drying of the imageby the drying heater 41.

The drying heater 41 is arranged to the downstream side in the transportdirection (the Y2 direction shown in FIG. 2) in relation to the head 31,and dries the image formed by the ink composition ejected from the head31. The drying heater 41 is arranged adjacent to the air blower 43. Thecuring heater 42 further dries and cures the image which was dried usingthe drying heater 41, and is arranged to the downstream side in thetransport direction in relation to the drying heater 41.

The detector group 50 includes a linear encoder, a rotary encoder, apaper detection sensor, an optical sensor, and the like. The linearencoder detects the position of the carriage in the movement direction.The rotary encoder detects the rotation amount of the transport roller12. The paper detection sensor detects the position of the distal end ofthe paper (medium to be recorded P) during feeding. The optical sensordetects the presence of the medium to be recorded P by fitting a lightemitting portion and a light receiving portion to the carriage. Theoptical sensor detects the position of an end portion of the medium tobe recorded P while moving in accordance with the carriage, and candetect the width of the medium to be recorded P. In addition, theoptical sensor can also detect the distal end (also referred to as theend portion to the downstream side in the transport direction, or theupper end) or the rear end (also referred to as the end portion to theupstream side in the transport direction, or the lower end) of themedium to be recorded P according to the situation.

The controller 60 is a control unit for performing control of theprinter 1. The controller 60 includes a CPU 62 and a unit controlcircuit 64. The interface unit 61 performs transceiving of data betweenthe computer 100, which is an external apparatus, and the CPU 62. TheCPU 62 is a processing unit for performing overall control of theprinter 1. Memory 63 is for securing a region which stores programs ofthe CPU 62, an operation region, or the like, and includes a memoryelement such as RAM or EEPROM. The CPU 62 controls each unit via theunit control circuit 64 in accordance with the program stored in thememory 63.

When performing printing, the controller 60, as described below,alternately repeats a dot formation operation which ejects the inkcomposition from the head 31 during movement in the movement direction,and a transport operation which transports the medium to be recorded Pin the transport direction, and prints the image (including thefinishing coat image) configured from a plurality of dots to the mediumto be recorded P. In this manner, the ink jet recording apparatus usingthe above-described ink composition forms an image (including thefinishing coat image) on a region of the printed medium P opposing thehead 31.

Modification Examples of Ink Jet Recording Apparatus

The recording apparatus described above is an off-carriage type serialprinter. While not shown, in a case in which a large capacity ink tankis additionally provided on the outside of the printer 1, an ink supplytube connects between the large capacity ink tank and the ink cartridge.Accordingly, in the same manner as in an on-carriage type printer, it isalso possible to greatly increase the storage amount of the inkcomposition in the off-carriage type printer 1.

In addition, the recording apparatus of the present embodiment may alsobe the on-carriage type serial printer, in which an ink cartridge (inktank) is installed together with the head 31 on the carriage. In thecase of the on-carriage type, the carriage holds an ink cartridge, whichaccommodates the ink composition, in a removable manner. In addition,the recording apparatus of the present embodiment may also be a lineprinter in which recording is performed without the head movingsubstantially.

Second Embodiment Ink Jet Recording Method

The ink jet recording method (hereinafter, also referred to as simplythe “recording method”) according to the second embodiment may performrecording using the ink jet recording apparatus 1 according to the firstembodiment. The ink jet recording method according to the presentembodiment includes at least the first recording step and the secondrecording step described below. In addition, it is preferable that theink jet recording method according to the present embodiment include afirst drying step to be performed during the execution of the secondrecording step or after the second recording step, and a second dryingstep to be executed after the first drying step at a second temperaturewhich is a temperature that exceeds the first temperature of the firstdrying step.

Below, description will be given of a recording method which performstransport in the reverse direction to the transport path of the mediumto be recorded P, the recording method which incorporates the so-calledback-feed, with reference to FIG. 2, and each step in relation to theink jet recording method according to the second embodiment will bedescribed in detail. FIG. 2 is a schematic cross-sectional view of theink jet recording apparatus 1 which executes the ink jet recordingmethod that incorporates the back-feed.

First Recording Step

In the first recording step, an image is formed by recording the firstink composition onto the medium to be recorded P which is non-absorbentor poorly absorbent to ink using the head 31. In other words, an imageformed from the first ink composition is formed by ejecting the firstink composition from the head 31 toward the medium to be recorded P soas to attach it thereto (land it thereon). In the first recording step,it is possible to form the image by using ink compositions of variouscolors. For example, it is possible to form an image using inkcompositions of the four colors of CMYK, or to form an undercoat whichgives excellent opacity to the medium to be recorded using a white inkcomposition. Furthermore, the first recording step is considered to becomplete at the point in time that the first ink composition ejectedfrom the head 31 has formed a film (become a film).

In particular, in the case of a recording method that has incorporatedthe back-feed, as shown in FIG. 2, the first printing step is executedat the same time as the transport operation in the forward direction ofthe sub-scanning direction (the Y direction in the drawings) of themedium to be recorded P, in other words, the direction (Y1 direction)from the upstream side to the downstream side in the transportdirection. In addition, in the first recording step, the image is formedby ejecting the first ink composition from the nozzle holes within thehead 31 toward the medium to be recorded P, and landing the first inkcomposition thereon, in the main scanning direction of a directionsubstantially orthogonal to the sub-scanning direction. In this case, inthe recording method using a serial printer, multi-pass printing, inwhich a number of passes (number of main scans) is two or more, ispossible. By forming the image by coating multiple layers of the inkcomposition divided into two or more passes using the multi-passprinting, it is possible to obtain an image of superior quality.

First Drying Step

The ink jet recording method of the present embodiment further includesa first drying step. The first drying step may be performed using aplurality of drying units (heaters). In the first drying step, the stepis performed during the execution of the first recording step or afterthe first recording step, but before the second recording step which isdescribed below, and the image is dried at a specific temperature (thismay be a plurality of temperatures, and may also be the same as thefirst temperature or the second temperature described below).Furthermore, it is preferable that the dryness factor of the imageformed by the first recording step before the second recording step be60% or higher (it is preferable to further use a curing heater 42together with the heater). The layer formed from the second inkcomposition has a high glossiness due to the dryness factor of the imagebefore the second recording step being 60% or higher. In addition, it ispossible to prevent the occurrence of bleeding between the image derivedfrom the first ink composition, and the second ink composition. Thedryness factor is, due to being able to increase the glossiness of theimage and in order to prevent the occurrence of bleeding yet moreeffectively, preferably 70% or higher, and more preferably 80% orhigher.

Furthermore, the “dryness factor” in the present specification iscalculated by dividing the difference between the mass of the inkcomposition during ejection and the mass of the ink composition afterdrying, by the difference between the mass of the ink composition duringejection and the mass of the ink composition after drying at a point intime that the mass change due to drying has substantially stopped. Forexample, the dryness factor in the first drying step is measured andcalculated in the manner described below. The mass of the medium to berecorded P when the first ink composition is applied to the medium to berecorded and the image is formed is equivalent to a dryness factor of0%. Furthermore, the point in time at which the image has been driedunder specific drying conditions and the mass change of the medium to berecorded P has substantially stopped is equivalent to a dryness factorof 100%. Using these two items of data and the mass data of the firstink composition at a point in time that the second ink composition isrecorded, it is possible to calculate the dryness factor. Furthermore,description will be given with reference to the graph of FIG. 4 whichshows the change over time of the dryness factor in a case where thedrying time has been changed in the first drying step.

In this manner, in the ink jet recording method according to the presentembodiment, the first recording step and the second recording step willnot be (substantially) performed at the same time by performing thesecond recording process described below after setting the drynessfactor of the image obtained by the first recording step to 60% orhigher by using the first drying step. Therefore, the problem of the inkcomposition bleeding is not present, and the application amount of theink composition is not particularly limited.

The drying for setting the dryness factor of the image to 60% or higher(hereinafter, also referred to as the “drying of a dryness factor of 60%or higher”) is performed using at least the drying heater 41 (preferablyused together with the curing heater 42). As shown in FIG. 2, since thedrying heater 41 adjoins the head 31 which ejects the first inkcomposition, the ejection and drying of the first ink composition areperformed at (substantially) the same time. In other words, the mediumto be recorded P (substantially) does not move in the sub-scanningdirection while the first recording step and the first drying step arebeing performed. As the drying heater 41, there are no particularlimitations, however for example, an infrared heater, a warm air heater,and a hot air heater may be exemplified. Among these, the infraredheater, in which heating is extremely fast (the rate of temperatureincrease), is preferable because it is possible to heat only the mediumto be recorded P. Furthermore, since the dryness factor of the image isset to 60% or higher in a preferable first drying step, it is possibleto perform drying at the first temperature and subsequently performfurther drying at the second temperature which is a temperature higherthan the first temperature. In this case, it is possible to perform thefurther drying using the curing heater 42 which heats at the secondtemperature.

Back-Feed Step

In the back-feed step, the transportation of the medium to be recorded Pis performed in the reverse direction of the sub-scanning direction ofthe medium to be recorded P, in other words, the direction (the Y2direction shown in FIG. 2) from the downstream side to the upstream sideof the transport direction. More specifically, the medium to be recordedP obtained through the first recording step and the first drying step istransported in the Y1 direction shown in FIG. 2, or preferably, istransported in the Y1 direction until the medium to be recorded P is infront of the curing heater 42, after which the medium to be recorded Pis transported in the Y2 direction. Furthermore, in order to form adesired image, after completing the back-feed step without ejecting theink composition from the head 31 toward the medium to be recorded Pduring the back-feed step, it is preferable to eject the ink compositionwhen transporting toward the downstream side in the transport direction.

Second Recording Step

In the second recording step, recording is performed by ejecting thesecond ink composition onto the medium to be recorded P in relation toan image dried in the first drying step using the head 31. In otherwords, the second ink composition forms a finishing image coated on theimage formed using the colored ink composition by ejecting the secondink composition from the head 31 toward an image formed using a coloredink composition in the first recording step so as to attach (land) thesecond ink composition thereto. In this manner, the image in the presentembodiment is completed by being formed in stages. Furthermore, thesecond recording step is considered to be complete at the point in timethat the second ink composition ejected from the head 31 has formed afilm (become a film).

In particular, in a case of the recording method including a back-feedstep, the second recording step is performed during the execution of thetransporting operation to the Y2 direction shown in FIG. 2, or after thetransporting operation to the Y2 direction. In addition, in the secondrecording step, the finishing coat image is formed by ejecting thesecond ink composition from the nozzle holes within the head 31 towardthe image obtained in the first recording step, and landing the secondink composition thereon. Furthermore, the second recording step may alsoperform the recording using the second ink composition whiletransporting in the Y1 direction after completing the transportingoperation to the Y2 direction. In addition, as shown in FIG. 2, the head31 in the second recording step is the same as the head 31 in the firstrecording step, and therefore it is possible to further miniaturize therecording apparatus. Furthermore, the head 31 in the first recordingstep and the head 31 in the second recording step may also be differentheads.

It is possible to form a recorded object (image) with excellentglossiness and color fastness to rubbing by applying a finishing coat ofthe second ink composition using the second recording step. Furthermore,in a case of making the glossiness and the color fastness to rubbing ofthe recorded object (image) superior, it is preferable to perform therecording operation in the second recording step two or more times. Inother words, it is preferable that the second recording step record(finish coat) the second ink composition to the image obtained in thefirst recording step, and re-record (finish coat) the second inkcomposition after the layer of the second ink (hereinafter, referred toas the “clear ink layer”) on the medium to be recorded P has dried. Inthis case, this may be referred to as the second coating of the secondink composition. Furthermore, in a case where the finish coatingdescribed above is performed, the compositions (the type and content ofthe formulation ingredients) of the second ink compositions whichconfigure each clear ink layer may be the same as, or different fromeach other.

Second Drying Step

The ink jet recording method of the present embodiment further includesa second drying step. In the second drying step, the step is performedduring the execution of the second recording step or after the secondrecording step, and the image formed using the second recording step isdried using the first temperature. It is preferable that the firsttemperature be 40° C. or higher and lower than 70° C. from a viewpointof ejection stability of the second ink composition, as described in thefirst drying step described above. Furthermore, in the second dryingstep, in a case that the dryness factor of the image is set to 60% orhigher, it is possible to perform drying at the first temperature andsubsequently perform further drying at the second temperature which is atemperature higher than the first temperature. In this case, it ispossible to perform the further drying using the curing heater 42 whichheats at the second temperature. In addition, since the drying ispromoted when drying the image using at least the drying heater 41 inthe second drying step, an air blower 43 may also be used.

The first temperature in the second drying step is, as described below,at least below the heat deformation temperature of the resin containedin the second ink composition. When the first temperature is below theheat deformation temperature of the resin, it is possible to prevent thehead 31 from being damaged by the heat. The specific temperature of thefirst temperature is preferably from 40° C. to 60° C. in order tosatisfy all of the conditions described above. In addition, in order topromote drying in the second drying step, an air blower 43 may also beused. The air blower 43 may also supply either air of an ambienttemperature or cold air. In addition, it is preferable to arrange theair blower 43 in the vicinity of the drying heater 41, in other words,in the vicinity of the head 31.

Furthermore, in a case of the recording method including a back-feedstep, it is preferable for the second drying step to execute the seconddrying step after each recording step in a case where the recordingoperation in the second recording step is performed two or more times.Accordingly, it is possible to make the glossiness and the colorfastness to rubbing of the recorded object (image) superior.

Third Drying Step

It is preferable that the ink jet recording method of the presentembodiment further include a third drying step. The third drying step isexecuted after the second drying step. The third drying step is a dryingstep using the second temperature, and is preferably performed using thecuring heater 42 which is set to the second temperature. As describedabove, the second temperature is set higher than the first temperature,and is set to a temperature which cures and fixes the image using thesecond ink composition formed in the second recording step by furtherincreasing the dryness factor thereof.

The second temperature, at which the dryness factor of the third dryingstep becomes 70% or higher, is set, and as described below, ispreferably set to at least above the film forming temperature (MFT:Minimum Film Forming Temperature), or above the glass transition pointTg of the resin contained in the second ink composition. Since the resindescribed above melts and the rough surface appearance or irregularappearance of the finishing coat image are almost entirely eliminateddue to setting the second temperature to MFT or Tg or higher, theglossiness is superior. The specific temperature of the secondtemperature is preferably from 70° C. to 120° C., and more preferablyfrom 80° C. to 110° C. in order to satisfy all of the conditionsdescribed above. Furthermore, the MFT will be described below.

Due to the ink jet recording apparatus 1 which executes the above stepsincluding a back-feed step and performing transportation periodically inthe reverse direction (the Y2 direction) to the transport direction (theY1 direction shown in FIG. 2) of the medium to be recorded P, it ispossible to minimize the number of heaters provided in the head 31 andthe heater unit 40, and therefore it is possible to realizeminiaturization of the recording apparatus.

Modification Examples of Ink Jet Recording Method

1. Recording that does not Perform Back-Feed

As a modification example of the recording method of the presentembodiment, leaving the medium to be recorded P stationary withouttransporting it and performing drying using the drying heater 41 ornatural drying is exemplified instead of performing the back-feedrecording which performs transportation in the reverse direction to thetransport path of the medium to be recorded P.

2. Recording Using Division of Nozzle Rows

As another modification example of the recording method of the presentembodiment, performing a divided recording which performs recording bydividing the nozzle rows into groups of a specific number of nozzleholes may be exemplified. The ink jet head 31 used in the firstrecording step scans in the main scanning direction through a scanningmechanism, and is provided with a nozzle row formed from a plurality ofnozzle holes. Furthermore, the nozzle rows include a first nozzle row inwhich a plurality of the nozzle holes for ejecting the first inkcomposition are arranged in a sub-scanning direction intersecting themain scanning direction, and a second nozzle row in which a plurality ofthe nozzle holes for ejecting an undercoat ink composition which recordsan undercoat layer of the image are arranged in the sub-scanningdirection. At this time, the method in which the first recording stepuses the first nozzle row and the second nozzle row divided in thesub-scanning direction into groups which respectively include apredetermined number of the nozzle holes, records the undercoat inkcomposition using a first group in the upstream side in the sub-scanningdirection, and, records the first ink composition using a second groupfurther to a downstream side in the sub-scanning direction than thefirst group, is referred to as the recording method using division.Below, the recording method will be described with reference to FIG. 3.FIG. 3 is a schematic view representing the recording unit using dividednozzle rows.

As shown in FIG. 3, the nozzle row 16 of a nozzle row 16A and a nozzlerow 16B in which a plurality of nozzle holes 17 are formed in thesub-scanning direction is used divided into a first group on theupstream side T1 in the sub-scanning direction, and a second groupfurther to the downstream side T2 in the sub-scanning direction than thefirst group. First, droplets of the undercoat ink composition areejected from the first group of the first nozzle row 16A while movingthe carriage 4 in the main scanning direction (S1 and S2), and thedroplets of the undercoat ink composition are attached onto the mediumto be recorded P.

Next, the medium to be recorded P is moved to the downstream site T2direction in the sub-scanning direction by the amount of the length ofthe first group in the sub-scanning direction. Furthermore, the image isobtained by ejecting droplets of the first ink composition describedabove from the second group of the second nozzle row 16B while movingthe carriage 4 in the main scanning direction, and attaching thedroplets of the first ink composition onto the lower layer formed on themedium to be recorded P. In addition, it is also possible to perform inthe same manner in a case in which the nozzle row 16 is used dividedinto three or more. Furthermore, the undercoat ink composition is notparticularly limited, however, examples thereof include a white inkcomposition containing titanium dioxide and the like, and a glitter inkcomposition containing silver, aluminum and the like.

The recording method using the above-described division of the nozzlerows 16A and 16B is capable of achieving an increase in speed of therecording by dividing the nozzle rows 16A and 16B and using them. Inaddition, when the nozzle rows 16A and 16B are used divided, it ispossible to avoid back-feeding of the medium to be recorded P, or thenumber of back-feeds of the medium to be recorded P may be reduced.Accordingly, it is possible to reduce the misalignment which can occurdue to the back-feeding of the medium to be recorded P. In addition, ina preferable embodiment in a case where the undercoat ink composition isused, the image is formed by applying the undercoat ink composition andthe first ink composition using divided nozzle rows, the recordingmedium is transported to the downstream side in the transport directionand the image is dried using a heating mechanism on the downstream side.Furthermore, an embodiment is preferable in which back-feeding isperformed thereafter and the second ink composition is applied.

3. Recording Using Line Printer

Above, description has been given of the recording method and themodification examples in relation to the recording using a serialprinter. Meanwhile, in the case of recording using a line printer, dueto the structure of the printer, the same number of line heads isnecessary as the number of types of the ink composition. Therefore, forexample, as described above, in a case where the second ink compositionis recorded twice (two coatings are made) in relation to the imageobtained using the first recording step, two line heads for ejecting thesecond ink composition are necessary.

Ink Composition

The ink composition (including the first ink composition and the secondink composition, the same hereinafter) described above is used in theink jet recording method according to the embodiment described above.The first ink composition contains a color material. The second inkcomposition contains a resin and does not substantially contain a colormaterial. Here, “does not substantially contain” in the presentspecification refers to not containing an amount or greater in which themeaning of being added is sufficiently exhibited. Quantitatively, “doesnot substantially contain” means that the content in relation to thetotal mass (100 mass %) of the ink composition is 0.5 mass % or less,preferably 0.2 mass % or less, more preferably 0.1 mass % or less, evenmore preferably 0.05 mass % or less, and even more preferably 0.01 mass% or less. Below, description will be given in relation to an additive(component) which may or may not be contained in, or there is apossibility that it will be contained in the ink composition.

Color Material

The first ink composition contains a color material. It is possible touse at least one of a pigment and a dye for the color material.

Pigment

By using a pigment as the color material, it is possible to improve theglossiness of the ink composition. It is possible to use either of aninorganic pigment and an organic pigment as the pigment. As theinorganic pigment, it is possible to use carbon blacks (C. I. PigmentBlack 7) such as furnace black, lamp black, acetylene black, or channelblack, iron oxide, and titanium oxide.

Examples of the organic pigment include azo pigments such as insolubleazo pigments, condensed azo pigments, azo lake, and chelate azopigments; polycyclic pigments such as phthalocyanine pigments, peryleneand perinone pigments, anthraquinone pigments, quinacridone pigments,dioxazine pigments, thioindigo pigments, isoindolinone pigments, andquinophthalone pigments; dye chelates (for example, basic dye typechelates, acid dye type chelates, and the like), dye lakes (basic dyetype lakes, and acid dye type lakes), nitro pigments, nitroso pigments,aniline black, and daylight fluorescent pigments.

More specifically, examples of the carbon black used in a black inkinclude No. 2300, No. 900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7,MA8, MA100, No. 2200B, and the like (manufactured by Mitsubishi ChemicalCorporation), Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven1255, Raven 700 and the like (manufactured by Carbon Columbia), Regal400R, Regal 330R, Regal 660R, Mogul L, Monarch 700, Monarch 800, Monarch880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400and the like (manufactured by CABOT JAPAN K.K.), Color Black FW1, ColorBlack FW2, Color Black FW2V, Color Black FW18, Color Black FW200, ColorBlack 5150, Color Black 5160, Color Black 5170, Printex 35, Printex U,Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black4A, and Special Black 4 (manufactured by Degussa).

Examples of the pigment used in a white ink include C. I. Pigment White6, 18, and 21.

Examples of the pigment used in a yellow ink include C. I. PigmentYellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37,53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110,113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154,167, 172, and 180.

Examples of the pigment used in a magenta ink include C. I. Pigment Red1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22,23, 30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 88,112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176,177, 178, 179, 184, 185, 187, 202, 209, 219, 224, and 245, or C. I.Pigment Violet 19, 23, 32, 33, 36, 38, 43, and 50.

Examples of the pigment used in a cyan ink include C. I. Pigment Blue 1,2, 3, 15, 15:1, 15:2, 15:3, 15:34, 15:4, 16, 18, 22, 25, 60, 65, or 66,and C. I. Vat Blue 4, or 60.

In addition, examples of pigments other than magenta, cyan and yellowinclude, for example, C. I. Pigment Green 7, or 10, C. I. Pigment Brown3, 5, 25, or 26, and C. I. Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16,24, 34, 36, 38, 40, 43, or 63.

Furthermore, one type of the above pigments may be used alone or two ormore types thereof may be used together.

When the pigments are used together, the average particle diameterthereof is preferably 300 nm or smaller, and is more preferably from 50to 200 nm. When the average particle diameter is within the above range,it is possible to form an image with superior reliability such as theejection stability and the dispersion stability in relation to the inkcomposition, as well as being of excellent quality. Here, the averageparticle diameter in the present specification is measured using adynamic light scattering method.

Dye

It is possible to use a dye as the color material. The dye is notparticularly limited, and it is possible to use an acidic dye, a directdye, a reactive dye, and a basic dye as the dye. Examples of the dyeinclude, for example, C. I. Acid Yellow 17, 23, 42, 44, 79, or 142, C.I. Acid Red 52, 80, 82, 249, 254, or 289, C. I. Acid Blue 9, 45, or 249,C. I. Acid Black 1, 2, 24, or 94, C. I. Food Black 1, or 2, C. I. DirectYellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, or 173, C. I.Direct Red 1, 4, 9, 80, 81, 225, or 227, C. I. Direct Blue 1, 2, 15, 71,86, 87, 98, 165, 199, or 202, C. I. Direct Black 19, 38, 51, 71, 154,168, 171, or 195, C. I. Reactive Red 14, 32, 55, 79, or 249, and C. I.Reactive Black 3, 4, or 35.

Furthermore, one type of the above dyes may be used alone or two or moretypes thereof may be used together.

Since it is possible to obtain excellent concealment and colorreproduction, the content of the color material is preferably from 1 to20 mass % in relation to the total mass (100 mass %) of the inkcomposition.

Dispersant

In a case where the ink composition contains a pigment, in order tofurther improve the pigment dispersibility, the pigment may furthercontain a dispersant. As the dispersant, there are no particularlimitations, however for example, a dispersant typically used to preparea pigment dispersion such as a polymeric dispersant may be exemplified.Specific examples include dispersants with one or more types ofpolyoxyalkylene polyalkylene polyamines, vinyl-based polymers andcopolymers, acrylic-based polymers and copolymers, polyesters,polyamides, polyimides, polyurethanes, amino-based polymers,silicon-containing polymers, sulfur-containing polymers,fluorine-containing polymer, and epoxy resins as the main component.Examples of commercial polymer dispersants include the AJISPER seriesmanufactured by Ajinomoto Fine-Techno Co., Inc., the Solsperse series(Solsperse 36000 and the like) which may be obtained from Avecia Inc. orNoveon, the Dispervic series manufactured by BYK Chemie, and theDisparon series manufactured by Kusumoto Chemicals, Ltd.

Resin

The second ink composition according to the present embodiment containsa resin (resin particles). Due to the second ink composition containinga resin, the color fastness to rubbing of mainly the finishing coatimage may be made excellent.

Furthermore, the first ink composition according to the presentembodiment may contain a resin. However, in a case where the first inkcomposition does not contain a resin, since the concentration of thecolor material of the first ink composition may be increased relatively,it is possible not to damage the quality of the image.

In particular, when performing the drying step described above, the heatdeformation temperature of the resin is preferably the first temperatureor higher, and the second temperature or lower. When the heatdeformation temperature is the first temperature or higher, the cloggingstability of the head 31 is superior. Meanwhile, when the heatdeformation temperature is the second temperature or lower, since theresin melts and the surface of the finishing coat image becomessmoother, the glossiness of the image is superior.

Here, the “heat deformation temperature” in the present specification isthe temperature value represented by the glass transition temperature(Tg) or the Minimum Film Forming Temperature (MFT). Among these, sinceit is easier to ascertain the superiority or inferiority of theredispersibility of the resin with the MFT than with the Tg, it ispreferable that the heat deformation temperature be the temperaturevalue represented by the MFT. When the ink composition has excellentredispersibility of the resin, the clogging stability of the head 31 issuperior due to the ink composition not adhering. Furthermore, themethod given in the section of the embodiments will be adopted for theevaluation method of the redispersibility in the present specification.In addition, the Tg in the present specification is disclosed as thevalue measured by using the differential scanning calorimetry method.The MFT in the present specification is disclosed as the value measuredby using ISO 2115:1996 (title:Plastics—Polymer dispersions—Determinationof white point temperature and minimum film-forming temperature).

It is preferable that the volume based average particle diameter of theresin particles be from 50 to 200 nm. In a case where the averageparticle diameter is within the above range, it is possible to obtainsuperior glossiness, and clogging stability of the head 31, and to formthe finishing coat image of a desired quality over a long period.

The resin is not particularly limited to the following examples,however, examples include polyester resins such as aliphatic polyesterresins and aromatic polyester resins, vinyl resins such as polyvinylchloride resins, polyvinyl acetate resins, and polyvinyl alcohol resins,vinyl chloride-vinyl acetates, ethylene-acetate vinyl resins, polyvinylbutyral resins, and cellulose resins such as ethyl cellulose resins,cellulose acetate propionate resins, and nitrocellulose resins,(meth)acrylic resins such as poly(meth)acrylic resins,poly(meth)acrylate methyl resins, and poly(meth)acrylate ethyl resins,ethylene-(meth)acrylic resins, styrene-(meth)acrylic resins,ethylene-(meth)acrylate resins, urethane resins, polystyrene resins,polycarbonate resins, phenoxy resins, polyamide resins, polyimideresins, polysulfane-based resins, petroleum resins, chlorinatedpolypropylene resins, polyolefin resins, ethylene-alkyl(meth)acrylateresins, rosin-modified phenolic resins, and various types of syntheticrubber such as NBR, SBR, and MBR, as well as modifications of the above.When the resin is one of these components, it is possible to obtain afinishing coat image of excellent glossiness and color fastness torubbing. In addition, it is possible to obtain superior glossiness, andclogging stability, and to form the finishing coat image of an excellentquality over a long period.

Among these, the resin is preferably one or more types selected from anacrylic resin, a urethane resin, a polyester resin, and astyrene-acrylic resin, since they have excellent durability.

In addition, among the resins, those which can form an emulsion arepreferable. When a resin which can form an emulsion as a resin isselected, it is possible to fix the second ink composition yet moreeffectively on the image formed using the first ink composition due to afilm being formed by drying.

Among these, a water-based urethane resin emulsion is preferable.Examples of commercial products include Mowinyl 972 (solidsconcentration 50%), 6530 (solids concentration 44%), and 742A (solidsconcentration 46%) (trade names) manufactured by Nippon SyntheticChemical Industry Co., Ltd., VINYBLAN 2500E (solids concentration 35%)(trade name) manufactured by Nissin Chemical Industry CO., Ltd.,Superflex 110, 130, 170, 210, 300, 420, 420NS, 460, 470, 500, 610, 620,650, 700, 740, 860, 870, E-2000, E-2500, E-4000, E-4800, and R-5000(trade names) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., NeoRezR-9660, R-972, R-9637, R-967, and R-940 (trade names) manufactured byKusumoto Chemicals, and Adeka Bontighter HUX-380, 401, 290K, 394, and680 (trade names) manufactured by Adeka.

The resin may be either anionic, nonionic, or cationic. Among these,nonionic or anionic is particularly preferable from a viewpoint ofhaving suitable material properties for the head 31. In addition, onetype of the resin may be used in isolation, and two types or more mayalso be used together.

The content of the resin in relation to the total mass (100 mass %) ofthe second ink composition is preferably from 1 to 30 mass %, and morepreferably from 5 to 10 mass %. In a case where the resin is within theabove ranges, it is possible to obtain a formed finishing coat image ofsuperior glossiness and color fastness to rubbing.

Surfactant

The ink composition according to the present embodiment may contain asurfactant. As the surfactant, it is preferable to use an acetyleneglycol-based surfactant or a polysiloxane-based surfactant. Theacetylene glycol-based surfactant or the polysiloxane-based surfactantimprove the affinity (wettability) of the recorded surface in the mediumto be recorded P, such that it is possible to improve the permeabilityof the ink composition.

A commercial product may be used as the acetylenic glycol surfactant,examples of which include Olefin E1010, STG, or Y (trade names)manufactured by Nissin Chemical Industry Co., Ltd., Surfynol 104, 82,465, 485, or TG (trade names) manufactured by Air Products and ChemicalsInc.

A commercial product may be used as the polysiloxane surfactant,examples of which include BYK-347 or BYK-348 (trade names) manufacturedby BYK-Chemie Co., Ltd.

Furthermore, the ink composition may also contain an anionic surfactant,a nonionic surfactant, an amphoteric surfactant, or the like, as well asother surfactants. In addition, one type of the surfactant may be usedin isolation, and two types or more may also be used together.

The content of the surfactant is not particularly limited, however, itis favorably from 0.1 to 1.0 mass % in relation to the total mass (100mass %) of the ink composition.

Water-Soluble Organic Solvent (Wetting Agent)

In order to prevent clogging in the vicinity of the nozzle holes 17 ofthe head 31, the ink composition may also contain a water-solubleorganic surfactant (wetting agent) which provides a wetting effect. Thewetting agent is not particularly limited to the following examples,however, examples include multivalent alcohols such as 1,2-hexanediol,glycerin, 1,2,6-hexane triol, trimethylol propane, ethylene glycol,propylene glycol, butylene glycol, diethylene glycol, triethyleneglycol, tetraethylene glycol, pentaethylene glycol, dipropylene glycol,2-butene-1,4-diol, 2-ethyl-1,3-hexanediol, and 2-methyl-2,4-pentanediol,sugars such as glucose, mannose, fructose, ribose, xylose, arabinose,galactose, aldonic acid, glucitol (sorbitol) maltose, cellobiose,lactose, sucrose, trehalose, and maltotriose, so-called solid wettingagents such as sugar alcohols, hyaluronic acids, and ureas, alkylalcohols having 1 to 4 carbon atoms such as ethanol, methanol, butanol,propanol, and isopropanol, so-called amino acids such as pyrrolidonecarboxylic acid, aspartic acid, glycine, glycine, proline, and betaine,as well as 2-pyrrolidone, N-methyl-2-pyrrolidone,1,3-dimethyl-2-imidazolidinone, formamide, acetamide, dimethylsulfoxide, sorbitol, sorbitan, acetin, diacetin, triacetin, andsulfolane.

One type of the water-soluble organic solvent may be used in isolation,and two types or more may also be used together.

In addition, in order to secure suitable physical properties (viscosityand the like) of the ink composition as well as favorable print qualityand reliability, the content of the water-soluble organic solvent isfavorably from 5 to 30 mass % in relation to the total mass (100 mass %)of the ink composition.

Furthermore, it is preferable that the first ink contain 0.5 mass % ormore of 1,2-hexanediol and that the second ink does not substantiallycontain 1,2-hexanediol. Including the 1,2-hexanediol solvent improvesthe ejection stability, however, although the reason is not clear,including it in the second ink causes an issue in that the glossinessdecreases. Although the reason is not known, it is possible that1,2-hexanediol influences the dispersibility of the resin particles inthe second ink.

Aprotic Polar Solvent

It is preferable that the second ink composition not substantiallycontain an aprotic polar solvent. This is because the redispersibilityof the resin contained in the second ink composition improves and theejection stability is excellent due to the second ink composition notsubstantially containing an aprotic polar solvent. It is preferable toadd an aprotic polar solvent to the first ink composition depending onthe type of the medium to be recorded P. This is because, in particular,the adherence of the ink composition to the medium to be recorded P suchas vinyl chloride is superior due to the first ink compositioncontaining an aprotic polar solvent.

The aprotic polar solvent is not particularly limited to the followingexamples, however, it is preferable to select one type or more from agroup formed from pyrrolidones, lactones, sulfoxides, imidazolidinones,sulfolanes, urea derivatives, dialkyl amides, cyclic ethers, glycoldiethers, and amide ethers.

Specific examples of pyrrolidones include 2-pyrrolidone,N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone. Specific examples oflactones include γ-butyrolactone, γ-valerolactone, and ε-caprolactone.Specific examples of sulfoxides include dimethyl sulfoxide andtetramethylene sulfoxide. A specific example of an imidazolidinone is1,3-dimethyl-2-imidazolidinone. Specific examples of sulfolanes includesulfolane and dimethyl sulfolane. Specific examples of ureas includedimethyl urea and 1,1,3,3-tetramethyl urea. Specific examples ofdialkylamides include dimethylformamide and dimethylacetamide. Specificexamples of cyclic ethers include 1,4-dioxane and tetrahydrofuran. Aspecific example of a glycol diether is diethylene glycol diethyl ether.

In addition, the solvent represented by the following General Formula isequivalent to the amide ether.

In the formula, it is appropriate for R¹ to be an alkyl group havingfrom 1 to 4 carbon atoms. The “alkyl group having from 1 to 4 carbonatoms” may be a linear or a branched alkyl group, for example, may be amethyl group, an ethyl group, an n-propyl group, an iso-propyl group, ann-butyl group, an iso-butyl group, a sec-butyl group, or a tert-butylgroup. The solvent represented by the formula in which R¹ is an alkylgroup having from 1 to 4 carbon atoms can give an appropriatepseudoplasticity to the ink composition, and therefore it is possible tosecure favorable ejection stability of the ink. In addition, the solventrepresented by the formula in which R¹ is an alkyl group having from 1to 4 carbon atoms is preferable particularly because the resin solvencyaction is strong.

The HLB value of the solvent represented by the formula is preferablyfrom 10.5 to 20.0, and more preferably from 12.0 to 18.5. When the HLBvalue of the solvent represented by the formula is within the aboverange, this is even more favorable since an appropriate pseudoplasticitycan be given to the ink, and due to the interaction with the resincomponent.

Furthermore, the HLB value of the solvent represented by the formula isa value calculated from the ratio between the nonpolar value (I) and theorganic value (O) (hereinafter also simply referred to as the “I/Ovalue”) in an organic conceptual diagram.HLB value=(nonpolar value(I)/organic value(O))×10

Specifically, the I/O value may be calculated based on the respectivedocuments “Systematic Organic Qualitative Analysis Mixtures” by BokuFujita, published by Kazama bookstore, 1974, “Theoretical Chemistry ofDyeing” by Nobuhiko Kuroki, published by Maki bookstore, 1966, and“Organic Compound Separation Method” by Hiro Inoue, published by ShokaboPublishing, 1990.

In a case where the ink composition contains an aprotic polar solvent,since the favorable effect, in that the fixability in relation to therecording medium is improved, may be obtained, it is preferable toselect one type or more from the group formed from pyrrolidones,lactones, sulfoxides, amides and ethers.

Water

The ink composition used in the ink jet recording method according tothe embodiment described above preferably contains water as the mainsolvent. Examples of the water include ion-exchange water, ultrafilteredwater, reverse osmosis water, pure water such as distilled water, orultrapure water. Among these, water which has been sterilized usingultraviolet radiation, the addition of hydrogen peroxide, or the like ispreferable since it prevents mold or bacteria from arising and makeslong-term storage of the ink composition possible.

Other Additives

The ink composition according to the present embodiment may containadditives other than those described above (other additives). Examplesof such additives include penetration enhancers such as pH modifiers,preservatives, fungicides, and glycol ethers, antioxidants, and thelike.

The medium to be recorded P used in the ink jet recording method of theembodiment described above is a medium which is non-absorbent or poorlyabsorbent to ink to be recorded. The term “medium which is non-absorbentor poorly absorbent to ink to be recorded” refers to whether or not anink reception layer (acceptance layer) is provided, or to a medium to berecorded provided with a reception layer not having enough thickness inorder to sufficiently exhibit a function as a reception layer. Morequantitatively, the term “medium which is non-absorbent or poorlyabsorbent to ink to be recorded” refers to a medium to be recorded inwhich the water absorption amount from the initiation of contact withthe 30 msec^(1/2) point is 10 mL/m² or less according to the Bristowmethod.

The details of the Bristow method are disclosed in the standard No. 51“Paper and Cardboard—Liquid Absorbency Test Method—Bristow Method” ofthe “JAPAN TAPPI Paper Pulp Test Method 2000 Edition”. The Bristowmethod is, to summarize, a method in which the wetting of a liquid tothe surface of a medium to be recorded, and subsequently, the osmosisbehavior of the liquid on the medium to be recorded are measured in ashort time in millisecond units, and in which the liquid is dynamicallymoved from the head box to the test specimen above the rotating wheeland the absorption function Ka [unit: mL/m²·(msec^(1/2))] is obtainedfrom the absorption time and transition amount.

The medium to be recorded P which is non-absorbent to ink is not limitedto the following, however, examples thereof include a recording mediumin which plastic is coated onto a substrate, such as a plastic film orpaper, which has not undergone surface processing for ink jet recording,in other words does not have an ink reception layer, and a recordingmedium in which a plastic film is bonded onto a substrate, such as aplastic film or paper, which has not undergone surface processing forink jet recording, in other words does not have an ink reception layer.The plastic is not limited to the following, however, examples thereofinclude polyvinyl chloride, polyethylene terephthalate, polycarbonate,polystyrene, polyurethane, polyethylene, and polypropylene.

The ink low-absorption medium to be recorded P is not limited to thefollowing, however, examples thereof include coated paper, and printingpaper such as fine coated paper, art paper, coated paper, matte paper,and cast paper.

Coated paper refers to paper in which a coating is coated on the surfaceto improve the aesthetics and the smoothness thereof. The coating may beprepared by mixing talc, pyrophyllite, clay (kaolin), titanium oxide,magnesium carbonate, and pigments such as calcium carbonate, andadhesives, such as starch and polyvinyl alcohol. The coating is coatedusing a coater during the manufacturing process of the paper. As thecoater, there is an off-machine-type coater which performs paper makingand coating as one process by being directly connected to a papermachine, and an on-machine-type coater which performs paper making as aseparate process.

Fine coated paper refers to recording paper in which the coating amountof the coating is 12 g/m² or less.

Art paper refers to recording paper in which approximately 40 g/m² ofcoating is coated onto high quality paper (high grade recording paper).Coated paper refers to recording paper to which approximately 20 g/m² to40 g/m² of coating is coated. Cast paper refers to recording paper whichis finish coated to have superior metallic glossiness and smoothness byapplying pressure to the surface of art paper or coated paper using acast drum.

It is possible to provide an ink jet recording method with excellentglossiness and clogging stability of the head 31 by using the inkcomposition and the medium to be recorded P described above. Morespecifically, it is possible to obtain a coating film with excellentglossiness, and, to increase the ink application amount, since there isno concern that bleeding will occur.

Example 1

Hereinafter, further specific description will be given of theembodiments of the invention using examples, however, the embodimentsdescribed above are not limited to only these examples.

Color Materials Used

The materials used in the following examples, comparative examples,reference examples, and test examples are as follows.

Resin Emulsion

Mowinyl 972 (trade name, manufactured by Nippon Synthetic Chemical Co.,50% solids concentration)

Mowinyl 6530 (trade name, manufactured by Nippon Synthetic ChemicalIndustry, 44% solids concentration)

Mowinyl 742A (trade name, manufactured by Nippon Synthetic Chemical Co.,46% solids concentration)

VINYBLAN 2500E (trade name, manufactured by Nissin Chemical Co., 35%solids concentration)

Pigment

Carbon Black (hereinafter, also referred to as “K”)

Pigment Blue 15:3 (hereinafter also referred to as, “C”)

Pigment Red 122 (hereinafter also referred to as “M”)

Pigment Yellow 155 (hereinafter also referred to as “Y”)

Water-Soluble Organic Solvent

1,2 hexane diol

2-pyrrolidone (hereinafter also referred to as “2-P”)

butylene glycol (hereinafter also referred to as “BG”)

Surfactant

BYK-348 (trade name of BYK-Chemie Co., Ltd.)

Water

pure water

Preparation of Pigment Dispersion

Here, the pigment was dispersed using the following method.

A solution of water-soluble resin was prepared by 40 parts by mass ofthe dispersion resin (as a water-soluble resin methacrylic acid/butylacrylate/styrene/hydroxyethyl acrylate=a water-soluble resincopolymerized in a mass ratio of 25/50/15/10, weight-average molecularweight 12000) being introduced into a mixed liquor of 7 parts by mass ofpotassium hydroxide, 23 parts by mass of water, and 30 parts by mass oftriethylene glycol-mono-n-butyl ether, and dissolved by heating andstirring at 80° C. 1.75 kg of this solution (43% solids) was mixed with3.0 kg of each of the above pigments, ethylene glycol 1.5 kg, and 8.75kg of water, then pre-mixing was performed using an agitator to mix theabove. Dispersion of the pigment mixed liquor was performed using amulti-pass method by using a horizontal-type bead mill provided with amulti-disc-type impeller having 1.5 liters of effective volume andfilled to 85% with 0.5 mm zirconium beads. Specifically, the pigmentmixed liquor was obtained by performing two passes at a beadcircumferential speed of 8 m/second with an ejection amount of 30 litersper hour.

Next, circulation dispersion was performed by using a horizontal-typeannular-type bead mill having 1.5 liters of effective volume and filledto 95% with 0.05 mm zirconium beads. A pigment dispersion of 20% pigmentsolids was obtained by performing dispersion processing on 10 kg ofpigment mixed liquor for 4 hours using a screen with a pore size of0.015 mm, a bead circumferential speed of 10 m/second, and a circulationamount of 300 liters/hour.

Production of Ink Composition

The first ink composition (compositions 10 and 11) and the second inkcomposition (the clear ink composition) of composition 1 to composition9 were produced by mixing each ingredient by the contents shown in FIG.5, stirring them at room temperature for two hours, and then filteringusing a membrane filter with a pore size of 5 μm. A plurality of colorsof the first ink composition are prepared, however, they are the samecomposition except for the pigment being different (in other words, ofcompositions 10 and 11, since they are different by only the type of thepigment C, M, Y, and K, there are a total of 8 types of the first inkcomposition). Furthermore, the unit of content shown in FIG. 5 is mass%. In addition, the solids concentration of the resin in the clear inkcomposition is 7% in all of the colors. Furthermore, the term ink filmformation temperature in FIG. 5 corresponds to the MFT of the resincontained in the clear ink composition. In addition, in the ink jetrecording described below, film formation was performed on all of theclear ink compositions of each composition at the corresponding filmformation temperatures in FIG. 5.

Here, the redispersibility due to the resin emulsion in each of theclear ink compositions represented by composition 1 to composition 8, inother words, the redispersibility due to the difference in the MFT ofthe resins have been evaluated, and the results thereof are shown inFIG. 6. After drying the respective ink compositions of composition 1 tocomposition 8 shown in FIG. 5 at 50° C. for an hour, theredispersibility thereof was evaluated by visually observing whether ornot redispersion occurs when pure water was added. In FIG. 6, “O”represents that redispersion occurred, and “X” represents thatredispersion did not occur.

When the ink composition has excellent redispersibility, the cloggingstability of the head is superior due to the ink composition notadhering, in other words, the ink composition stably does not generatehead clogging. From FIG. 6, it was understood that the redispersibilityis excellent when the solvent (water-soluble organic solvent) is butylglycole (BG), and, the clear ink composition is Mowinyl 972 or Mowinyl6530 in which the MFT of the resin is 60° C. or higher.

Next, the characteristics of the recorded object due to the presence orabsence of an aprotic polar solvent in the first ink composition, inother words, the color ink composition were evaluated. The compositionsevaluated were the composition 10 and the composition 11, which arecolor ink compositions, shown in FIG. 5, where the composition 10contained 2-pyrolidone which is an aprotic polar solvent, and thecomposition 11 did not. The color fastness to rubbing was evaluated asthe evaluation item, and in the method of doing so, the recorded objectafter drying was set in a Gakushin-type color fastness to rubbing testmachine AB-301 (trade name, manufactured by Tester Sangyo Co., Ltd.),rubbed 10 times using a friction block (load; 300 g) in which a whitecotton cloth is attached to a contact portion (in accordance with JIS L0803), and those in which the color ink had not transferred to the whitecotton cloth were represented as an “O”, and those in which it had notas an “X”. The results are shown in Table 1.

TABLE 1 Evaluation of Color Fastness to Rubbing Composition 10 ◯Composition 11 X

As shown in Table 1, the color ink composition of composition 10, whichcontains 2-pyrrolidine as an aprotic polar solvent in the color inkcomposition which is the first ink composition, obtained an evaluationof having a high color fastness to rubbing.

Next, the characteristics of the recorded object due to the presence orabsence of 1,2-hexanediol, which is a 1,2-alkanediol having 4 to 6carbon atoms, in the clear ink composition which is the second inkcomposition were evaluated.

The compositions evaluated were the composition 1 and the composition 9,which are the clear ink compositions, shown in FIG. 5, where thecomposition 9 contained 1,2-hexanediol, and the composition 1 did not.The glossiness was evaluated, and when the average of the 20° specularglossiness on each color of CMYK was 60 or greater, this was shown as“O”, and when it was less than 60, this was shown as “X”.

TABLE 2 Evaluation of Color Fastness to Rubbing Composition 1 ◯Composition 9 X

As shown in Table 2, the clear ink composition of composition 1, whichdoes not contain 1,2-hexanediol in the clear ink composition which isthe second ink composition, obtained an evaluation of having a highglossiness.

From the above evaluation results, in the example shown below,composition 10 shown in FIG. 5 was used as the color ink composition ofthe first ink composition, and composition 1 and composition 2 were usedas the clear ink composition of the second ink composition.

Test Example 1

Next, the recorded object was manufactured in the following manner usingIJ40 (polyvinyl chloride) manufactured by 3M as the medium to berecorded, and the colored ink composition of composition 10, the clearink composition of composition 2, as well as the ink jet recordingmethod shown in FIG. 2.

First Recording Step

The first recording step was performed at the same time as performingthe transporting operation to the Y1 direction. The image was formed byejecting and landing the colored ink composition from the nozzles withinthe ink jet head toward the medium to be recorded. Furthermore, each ofthe conditions of the recording resolution was set to 720×1440 dpi, thenumber of scans to 10, the ejection weight per drop to 18 ng, and theduty to 100%.

First Drying Step

The first drying step was performed at the same time as the firstrecording step. The image was dried at 60° C. (the first temperature)using the drying heater 41 (infrared heater). At this time, the drynessfactor was 85%. Furthermore, the dryness factor was calculated based onthe mass at the time of the second recording step.

Furthermore, the air blower 43 which supplies cold air was used whendrying the image using the drying heater 41.

Back-Feed Step

In the back-feed step, the medium to be recorded which had undergone thefirst drying step was transported in the Y1 direction until it was infront of the curing heater 42, after which the medium to be recorded Pwas transported in the Y2 direction.

Second Recording Step

In the second recording step, the image in which the clear inkcomposition is finish coated onto the image (the finishing coat image)was formed by ejecting the clear ink composition from the nozzle rowswithin the ink jet head (the same ink jet head as in the first recordingstep) toward the image having a dryness factor of 85%, and landing theclear ink composition thereon. Furthermore, each of the conditions ofthe recording resolution was set to 720×1440 dpi, the number of scans to4, the ejection weight per drop to 18 ng, and the duty to from 0 to200%.

Second Drying Step

The second drying step was performed after the second recording step.The finishing coat image was dried at 100° C. (the third temperature)using the curing heater 42 (infrared heater) and was fixed onto themedium to be recorded. In this manner, the recorded object was obtained.

Test Examples 2 and 3

The compositions disclosed in the following Table 3 were adopted as thecolored ink composition and the clear ink composition, and the recordedobject was obtained in the same manner as in Test Example 1 except forthat the dryness factor was set to the values disclosed in Table 3.

Evaluation of the glossiness of the obtained recorded object wasperformed.

The 20° specular glossiness of the recorded object was measured inaccordance with JIS Z8741:1997 using a gloss meter (manufactured byNippon Denshoku Industries, trade name “GlossMeter model number VGP5000”). In addition, in the recording method of Test Example 2, thecolored ink composition and the clear ink composition were applied inorder using the divided application of the nozzle rows, and, in therecording method of Test Example 3, the colored ink composition and theclear ink composition were applied to the same location during the samescan.

TABLE 3 Test Example 1 Test Example 2 Test Example 3 Color InkComposition Composition Composition 10, Black 10, Black 10, BlackDryness factor 85% 50% 25% Clear Ink Composition 2 Composition 2Composition 2 Glossiness 40.9 25.2 10.1

Example 2

Next, the recorded object was manufactured in the following manner usingIJ40 (polyvinyl chloride) manufactured by 3M as the medium to berecorded, and the colored ink composition of composition 10, the clearink composition of composition 2, as well as the ink jet recordingmethod shown in FIG. 2.

First Recording Step

The first recording step was performed at the same time as performingthe transporting operation to the Y1 direction. The image was formed byejecting and landing the colored ink composition from the nozzle holeswithin the ink jet head toward the medium to be recorded. Furthermore,each of the conditions of the recording resolution was set to 720×1440dpi, the number of scans to 10, the ejection weight per drop to 18 ng,and the duty to 100%.

First Drying Step

The first drying step was performed at the same time as the firstrecording step. The image was dried at 60° C. using the drying heater 41(infrared heater). At this time, the dryness factor was 85%.Furthermore, the dryness factor was calculated based on the mass at thetime of the second recording step. In addition, the air blower 43 whichsupplies cold air was used when drying the image using the drying heater41.

Back-Feed Step

In the back-feed step, the medium to be recorded which had undergone thefirst drying step was transported in the Y1 direction until it was infront of the curing heater 42, after which the medium to be recorded Pwas transported in the Y2 direction.

Second Recording Step

In the second recording step, the image in which the clear inkcomposition is finish coated onto the image (the finishing coat image)was formed by ejecting the clear ink composition from the nozzle rowswithin the ink jet head (the same ink jet head as in the first recordingstep) toward the image having a dryness factor of 85%, and landing theclear ink composition thereon. Furthermore, the ejection method of theclear ink composition in the second recording step will be shown in thedrawings. The method 1 in FIG. 7 is a method of coating one layer of theclear ink composition at one time, and coating two layers using two timecoating. The method 2 is a method of coating two layers of the clear inkcomposition at one time. Further, the method 3 is a method of coatingone layer of the clear ink composition at one time.

Second Drying Step

The image was dried at 60° C. (the first temperature) using the dryingheater 41 (infrared heater). At this time, the dryness factor was 85%.Furthermore, the dryness factor was calculated based on the mass at thetime of the second recording step. In addition, the air blower 43 whichsupplies cold air was used when drying the image using the drying heater41.

Third Drying Step

The third drying step was performed after the second drying step. Thefinishing coat image was dried at 100° C. (the second temperature) usingthe curing heater 42 (infrared heater) and was fixed onto the medium tobe recorded. In this manner, the recorded object was obtained.Furthermore, in the coating method shown in FIG. 7, in the method 1, thesecond drying step was performed for each layer and per one time coatingwas performed, and the third drying step was executed after the secondperformance of the second drying step.

The evaluation of the glossiness of the recorded object obtained in thesteps described above based on the recording method shown in FIG. 8using the composition 1 and the composition 2 shown in FIG. 5 as theclear ink composition and the composition 10 shown in FIG. 5 as thecolor ink composition. In the evaluation method of the glossiness, the20° specular glossiness of the recorded object was measured inaccordance with JIS Z 8741:1997 using a gloss meter (manufactured byNippon Denshoku Industries, trade name “GlossMeter model number VGP5000”).

Furthermore, for comparison with examples 1 to 4, a system in which theclear ink composition is not finish coated was used as a test example.The results of the (20°) glossiness of the examples 1 to 4 and the testexample 4 are shown in FIG. 8.

In addition, the results of the (20°) glossiness of the examples 2 to 4and the test example 4 are shown in FIG. 9. Furthermore, in thefollowing table 5, the term “CMP” corresponds to the black imageproduced using a cyan ink (C), a magenta ink (M), and a yellow ink (Y).

From FIG. 8 and FIG. 9, the glossiness of example 1 and example 2 isexcellent, and, in particular, the glossiness of example 1 is excellent.In other words, the two layer two time coating of the method 1 shown inFIG. 7 can obtain a superior glossiness to the two layer one timecoating of the method 2, or the one layer one coating of the method 3.Furthermore, even in the coating method of the method 1, the clear inkcomposition as the second ink composition obtained a result in which thecomposition 2 shown in FIG. 5 obtained superior glossiness to thecomposition 1.

What is claimed is:
 1. An ink jet recording method using at least afirst ink composition containing a color material and a second inkcomposition containing a resin as well as substantially not containing acolor material, the method comprising: a first recording step of formingan image by recording the first ink composition onto a medium to berecorded which is non-absorbent or poorly absorbent to ink using an inkjet head; a second recording step of recording the second inkcomposition onto the image using the ink jet head; a second drying stepof drying the image at a first temperature, which is performed duringexecution of the second recording step or after the second recordingstep; and a third drying step of drying the image at a secondtemperature which exceeds the first temperature, and is performed afterthe second drying step, wherein, the second ink composition does notsubstantially contain an aprotic polar solvent, and the heat deformationtemperature of the resin exceeds the first temperature and is lower thanthe second temperature.
 2. The ink jet recording method according toclaim 1, wherein the first ink composition contains 1 mass % or more ofan aprotic polar solvent.
 3. The ink jet recording method according toclaim 1, wherein the first ink composition contains 0.5 mass % or moreof 1,2-hexanediol, and the second ink composition does not substantiallycontain 1,2-hexanediol.
 4. The ink jet recording method according toclaim 1, wherein the resin is one or more types selected from an acrylicresin, a urethane resin, a polyester resin, and a styrene-acrylic resin.5. The ink jet recording method according to claim 1, furthercomprising: a first drying step of drying the image at a firsttemperature performed during execution of the first recording step orbefore the second recording step, wherein the dryness factor of theimage formed by the first recording step before the second recordingstep is 60% or higher.
 6. The ink jet recording method according toclaim 1, wherein the second recording step includes a step of recordingthe second ink composition onto the image formed using the firstrecording step and re-recording the second ink composition after thesecond ink composition has dried on the medium to be recorded.
 7. Theink jet recording method according to claim 1, wherein the ink jet headused in the first recording step is provided with nozzle rows formedfrom a plurality of nozzle holes, and scans in a main scanning directionthrough a scanning mechanism; the nozzle rows include a first nozzle rowin which a plurality of the nozzle holes for ejecting the first inkcomposition are arranged in a sub-scanning direction intersecting themain scanning direction, and a second nozzle row in which a plurality ofthe nozzle holes for ejecting an undercoat ink composition which recordsan undercoat layer of the image are arranged in the sub-scanningdirection; and the first recording step uses the first nozzle row andthe second nozzle row divided in the sub-scanning direction into groupswhich respectively include a predetermined number of the nozzle holes,records the undercoat ink composition using a first group in an upstreamside in the sub-scanning direction, and, records the first inkcomposition using a second group further to a downstream side in thesub-scanning direction than the first group.
 8. A recording apparatus,wherein an image is formed on the medium to be recorded using the inkjet recording method according to claim
 1. 9. A recording apparatus,wherein an image is formed on the medium to be recorded using the inkjet recording method according to claim
 2. 10. A recording apparatus,wherein an image is formed on the medium to be recorded using the inkjet recording method according to claim
 3. 11. A recording apparatus,wherein an image is formed on the medium to be recorded using the inkjet recording method according to claim
 4. 12. A recording apparatus,wherein an image is formed on the medium to be recorded using the inkjet recording method according to claim
 5. 13. A recording apparatus,wherein an image is formed on the medium to be recorded using the inkjet recording method according to claim
 6. 14. A recording apparatus,wherein an image is formed on the medium to be recorded using the inkjet recording method according to claim
 7. 15. The ink jet recordingmethod according to claim 1, wherein the second drying step of dryingthe image at the first temperature is performed during execution of thesecond recording step.